ict 512 - advanced web technologies
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ICT 512 - Advanced Web Technologies. Lecture 1: Introduction Shakeel A. Khoja. Course outline 1/2. * Current Web data standards o XML, XSL, XLink, DOM, SMIL o Processing XML documents o Deploying XML data * Current Web metadata standards - PowerPoint PPT PresentationTRANSCRIPT
ICT 512 - Advanced Web Technologies
Lecture 1: Introduction
Shakeel A. Khoja
Course outline 1/2
* Current Web data standards o XML, XSL, XLink, DOM, SMIL o Processing XML documents o Deploying XML data
* Current Web metadata standards o RDF, RDF-SCHEMA o Ontologies, Dublin Core o Metadata processing o Surfing the semantic web
Course outline 2/2
* Hypertext Linking o Open Hypermedia philosophy o Hypertext history o The Missing Link: problems and solutions * Web Site Construction o Hypermedia Engineering o Hypermedia Development Methods o Hypermedia Development Techniques o Web Site Maintenance o Case study * Web Searching o Information retrieval history o Search engine algorithms o Case studies: Harvest, Google.
Books and references
Text Book: Munindar P. Singh and Michael N. Huhns, Service Oriented Computing Semantics, Processes, Agents, 2005, John Wiley.
Reference Books: Leon Shklar and Rich Rosen, Web Application
Architecture, 2nd Edition, JWI. Rosenfeld L, Information Architecture for the World
Wide Web, 2nd Edition, O'Reilly 2002 Deitel, Deitel and Goldberg, Internet and World
Wide Web - How To Program, 3rd Edition, Prentice Hall 2004
Gerti Kappel, Birgit Proll, Siegfried Reich, Werner Retschitzegger, Web Engineering, JWI 2006
Various WWW sources
Assessment Strategy
Assessment Method Contribution to the final mark
Mid Term Examinations: 30% (15 + 15)
Final Examination: 40%
Quizzes: 15%
Assignment / Mini Project: 15%
Enter 21st Century!
Our Information Landscape
Image from: http://www.socialmedia.biz/images/masssocialmedia.png
The Future of Information
Image from: http://novaspivack.typepad.com/nova_spivacks_weblog/metaweb_graph.JPG
What is 21st Century Business?
Buyers and sellers who are:
Effective Learners Effective Collaborators Effective Creators
Image from: http://www.uniquecare.org/Collaborate%20250.jpg
What do you think?
21st Century Learners: Lifelong learners Can learn how to
learn Independent learners Metacognitive Intrinsically motivated Focus on self
improvement
Image from: http://flickr.com/photos/akaicker/38149570/
21st Century Collaborators: Are effective communicators. Are socially and culturally aware. Take responsibility for their role. Are flexible.
Image from: http://flickr.com/photos/wainwright/351684037/.
21st Century Collaborators: Are able to delegate or
share responsibility when necessary.
Are equally comfortable as either leaders or participants.
Appreciate and internalize the essential interdependence of being part of society.
Image from: http://flickr.com/photos/pedrosimoes7/1301014184/
21st Century Creators: Effectively analyze and
synthesize. Originality, innovative
and creative contributors to society.
“think outside the box”. Systems thinkers. Goal oriented and
productive. Demonstrate ethical
responsibility.
Image from: http://flickr.com/photos/jimfrazier/525695141/
Why Go Global?
“The World is Flat” We are no longer
bound by four walls of classroom
Authentic development experiences
Image from: http://www.csupomona.edu/~sfenglehart/%20Hst%20Images%20/Berlin%20Wall.JPEG
Why Go Global?
Learning (and life) is networked, digital, connected.
Create an authentic classroom environment.
Image from: http://www.psychologicalscience.org/observer/2006/0306/images/old_classroom.jpg
Why Go Global?
Power of networks
Screen Shot from: Chrissy Hellyer @ Teaching Sagittarian: http://teachingsagittarian.edublogs.org/
New Interfaces?
Tap into the energy that people are bringing through new interfaces.
Image from: http://flickr.com/photos/bigduke6/90086641/
The Technology Toolbox
How to pick the right tools for the job
Image from: http://flickr.com/photos/mamabarns/747588843/
The Technology Toolbox
ToolBox: Blogs
When to use a blog: individual reflection seeking feedback
Grade 5 Student Blog: http://heejae.learnerblogs.org/
ToolBox: Blogs
Features of a blog: Entries posted in consecutive order,
newest on top Comments from readers extend
classroom learning Personal journal
Grade 5 Student Blog: http://heejae.learnerblogs.org/
ToolBoox: Wikis
When to use a wiki collaborative knowledge building
Grade 6 Student Wiki: http://ancientafricah.wikispaces.com
ToolBox: Social Networking
When to use Social Networks
Connecting students and teachers
Grade 4 Flat Classroom Project: http://connectedclassroom.ning.com/
Collaborative Multimedia
creative representation of ideas
Sample VoiceThread: http://voicethread.com/#home.b6073.i45532
ToolBox: VoIP
When to use VoIP Communicating with
personal learning network
Connecting on a personal level
ToolBox: VoIP
Features of VOIP Audio/video e-mail Audio/video chat Recording
discussions
7th Grade YackPack
The Ultimate Goal
Learning anytime, anywhere.
Develop a global Personal Learning Network
Communicate, Connect and Collaborate
Image from: http://prblog.typepad.com/strategic_public_relation/images/2007/06/22/simple_social_network.png
Chapter 1:Computing with ServicesService-Oriented Computing: Semantics, Processes, Agents– Munindar P. Singh and Michael N. Huhns, Wiley, 2005
Chapter 1
30Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Highlights of this Chapter
Visions for the Web Open Environments Services Introduced The Evolving Web Standards Bodies
Chapter 1
31Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
The Web As It Is
Not easy to program Designed for people to get information
Focuses on visual display (as in HTML) Lacks support for meaning
Supports low-level interactions HTTP is stateless Processing is client-server Creates avoidable dependencies among
what should be independent components
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32Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
The Web As It Is Becoming
Enable interactions autonomous, heterogeneous parties (information providers and users) Go beyond visual display to capture
meaning Semantic Web Support standardized interfaces Web
services Support complex activities processes Support rich interactions among
autonomous parties agents
Chapter 1
33Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Historical View of Services over the Web
Generation
Scope Technology
Example
First All Browser Any HTML page
Second Programmatic
Screen scraper
Systematicallygenerated HTMLcontent
Third Standardized
Web services
Formally described service
Fourth Semantic Semantic Web services
Semantically described service
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34Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Viewpoints on Services
Traditionally, a capability that is provided and exploited, often but not always remotely Networking: bundle of bandwidth-type properties Telecom: features (caller ID, forwarding) Systems: operational functions (billing, storage);
parceled up into operation-support systems Web or Grid: Web pages or Grid resources Wireless: Wireless access; messaging
By contrast, we treat services as resembling real-life services or business partners
Chapter 1
35Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
What is a Web Service?
A piece of business logic accessible via the Internet using open standards (Microsoft)
Encapsulated, loosely coupled, contracted software functions, offered via standard protocols (DestiCorp)
A set of interfaces providing a standard means of interoperating between different software applications, running on a variety of platforms and frameworks (W3C)
Our working definition: A service is functionality that can be engaged
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36Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Scope
Includes wherever Internet and Web technologies are employed
Internet Intranet: network restricted within an
enterprise Extranet: private network restricted to
selected enterprises Virtual Private Network (VPN): a way to
realize an intranet or extranet over the Internet
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37Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Service Composition
Vision Specify and provide services independently,
hiding implementations Use services in combination in novel ways Going beyond the idea of a passive object
Obviously desirable and challenging But is this what we want?
Can or should implementations be hidden? What about organizational visibility? How to assess risk? How to handle
exceptions?
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38Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Applications of Composable Services
Portals Legacy system interoperation E-commerce Virtual enterprises Grid computing
Chapter 1
39Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Autonomy
Independence of business partners (users and organizations)
Political reasons Ownership of resources Control, especially of access privileges Payments
Technical reasons Opacity of systems with respect to key
features, e.g., precommit in distributed databases
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40Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Heterogeneity
Independence of component designers and system architects
Political reasons Ownership of resources
Technical reasons Conceptual problems in integration Fragility of integration Difficult to guarantee behavior of
integrated systems
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41Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Dynamism
Independence of system administrators
Needed because the parties change Architecture and implementation Behavior Interactions
Make configurations dynamic to improve service quality and maintain flexibility
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42Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Locality: How to Handle the Above
Reduce sharing of data and metadata to reduce inconsistencies and anomalies
Reduce hard-coding, which reflects out-of-band agreements among programmers Bind dynamically to components Use standardized formats to express data Express important knowledge as metadata Use standardized languages to express
metadata Relax consistency constraints
Obtain remote knowledge only when needed Correct rather than prevent violations of
constraints: often feasible
Chapter 1
43Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
System Architectures: Centralized
Mainframe
Terminal3270
Terminal
Terminal
Terminal
Terminal
TerminalTerminal
Terminal
Terminal
Terminal
Terminal
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44Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
System Architectures: Client-Server
E-MailServer
WebServer
DatabaseServer
PCClient
PCClient PC
Client
WorkstationClient
Master-Slave
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45Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
System Architectures: Peer-to-Peer
E-MailSystem
WebSystem
DatabaseSystem
Application
ApplicationApplication
Application
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46Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
System Architectures: Cooperative
E-MailSystem
WebSystem
DatabaseSystem
Application
ApplicationApplication
Application
(Mediators, Proxies, Aides, Wrappers)
Agent
Agent
Agent
Agent
Agent
Agent
Agent
Agent
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47Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns
Chapter 1 Summary
Evolving perspectives on the Web Evolutions in IT architectures Open environments challenge some
fundamental assumptions of computer science Autonomy Heterogeneity Dynamism
Services, if understood correctly, can support IT in open environments